ui-router state constraints example

ui-router-better-state-constraints.js

// Protection for ui-router states
//
// usage:
//
// app.run(function($stateConstraints) {
//   
//   $stateConstraints.protect({
//     state : 'myState',
//     guard : function($currentUser) { // <- any service
//       // guard should return FALSE if transition to state should be cancelled
//       if ($currentUser.isSignedOut()) return false
//     };
//     onFail: function() {
//       alert("Signed users only");
//     }
//   });
//
// })
angular.module('app.services').service('$stateConstraints', function($injector, $rootScope) {

  var service = this;

  // list of all available guards
  this.guards = {
    signedEmployerOnly : function($currentSession, $state) {
      if ($currentSession.isSignedIn() && $currentSession.user.isEmployer()) {
        return true;
      } else {
        $state.go('default');
        return false;
      }
    },

    signedEmployerOwnerOnly : function($currentSession, $state, $stateParams) {
      if (service.guards.signedEmployerOnly($currentSession, $state)) {
        // TODO: check state params here
        return true;
      } else {
        return false;
      }
    },

    signedOutOnly : function($currentSession) {
      return $currentSession.isSignedOut() == true;
    }
  }

  // options -> { 
  //              guard: guardFunction, 
  //              state: 'stateName' 
  //            }
  this.protect = function protect(options) {
    $rootScope.$on('$stateChangeStart', function(event, toState, toParams) {
      if ( toState.name != options.state ) return;

      var guardResult = $injector.invoke(options.guard, undefined, { toParams: toParams, toState: toState });

      if (guardResult == false) {
        event.preventDefault();

        if ( _.isFunction(options.onFail) ) {
          $injector.invoke(options.onFail);
        } else {
          $injector.invoke(function($state) {
            console.log("request to " + toState.name + " declined with guard");
            $state.go('default');
          });
        }
      }
    }) 
  }

})

Usage example:

app.run(function($stateConstraints) {

  var $protect = $stateConstraints.protect;

  $protect({
    state : 'employer_profile',
    guard : $stateConstraints.guards.signedEmployerOnly,
    onFail: function() {
      console.log("employers only")
    }
  })

  $protect({
    state : 'vacancies',
    guard : $stateConstraints.guards.signedEmployerOnly
  }
}